Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
TETRA TECHNOLOGIES INC
  2. Issuer Name and Ticker or Trading Symbol
CSI Compressco LP [CCLP]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
Director by Deputization (9)
(Last)
(First)
(Middle)
24955 INTERSTATE 45 NORTH
3. Date of Earliest Transaction (Month/Day/Year)
09/10/2018
(Street)

THE WOODLANDS, TX 77380
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
___ Form filed by One Reporting Person
_X_ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Units representing limited partner interests 09/10/2018   M(1)(2)(3)(4)(5)(6)   85,830 A $ 5.51 (1) (2) (3) (4) (6) 15,689,983 I (7) see footnote (7)

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Series A Convertible Preferred Units (1) (2) (3) (4) 09/10/2018   M(1)(2)(3)(4)(5)(6)     41,375.2   (1)(2)(3)(4)   (8) Common Units representing limited partner interests (1) (2) (3) (4) $ 11.43 455,127.18 I (7) see footnotes (1) (2) (3) (4) (7) (9)

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
TETRA TECHNOLOGIES INC
24955 INTERSTATE 45 NORTH
THE WOODLANDS, TX 77380
      Director by Deputization (9)
Compressco Field Services, L.L.C.
24955 INTERSTATE 45 N
THE WOODLANDS, TX 77380
      Director by Deputization (9)
COMPRESSCO INC
24955 INTERSTATE 45 N
THE WOODLANDS, TX 77380
      Director by Deputization (8)
CSI Compressco GP Inc
24955 INTERSTATE 45 N
THE WOODLANDS, TX 77380
      Director by Deputization (9)

Signatures

 Bass C. Wallace, Jr., Sr. Vice President and General Counsel of TETRA Technologies, Inc., a Delaware corporation   09/12/2018
**Signature of Reporting Person Date

 Bass C. Wallace, Jr., Attorney-in-fact for Compressco Field Services, L.L.C., an Oklahoma limited liability company   09/12/2018
**Signature of Reporting Person Date

 Bass C. Wallace, Jr., Attorney-in-fact for Compressco, Inc., a Delaware corporation   09/12/2018
**Signature of Reporting Person Date

 Bass C. Wallace, Jr., General Counsel, Assistant Secretary, Assistant Treasurer of CSI Compressco GP Inc., a Delaware corporation   09/12/2018
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) On August 8, 2016, the Issuer entered into a Series A Preferred Unit Purchase Agreement (the "Purchase Agreement") with CSI Compressco Investment LLC ("CSI Investment") and the other purchasers party thereto (the "Purchasers"), whereby the Purchasers purchased 874,891 Series A Convertible Preferred Units representing limited partner interests in the Issuer (the "Preferred Units"). The Preferred Units were issued and sold to the Purchasers on August 8, 2016 (the "Closing"). The holders of the Preferred Units (each, a "Preferred Unitholder") will receive quarterly distributions in kind in additional Preferred Units, equal to an annual rate of 11.00% (2.75% per quarter), subject to certain adjustments. A ratable portion of the Preferred Units will be converted each month over a period of thirty months beginning in the seventh calendar month following the Closing (each, a "Conversion Date"), subject to certain provisions that may delay or accelerate all or a portion of such monthly
(2) conversions. On each Conversion Date, the Preferred Units will convert into common units representing limited partner interests in the Partnership ("Common Units") in an amount equal to, with respect to each Preferred Unitholder, the number of Preferred Units held by such Preferred Unitholder divided by the number of Conversion Dates remaining, subject to certain adjustments. The conversion price (the "Conversion Price") on any Conversion Date shall equal the least of (i) $12.00, subject to certain adjustments, (ii) 93.5% of the arithmetic average of the volume-weighted average trading price (the "VWAP") on each trading day during the twenty (20) trading day period immediately prior to such Conversion Date (subject to certain adjustments), and (iii) the arithmetic average of the VWAPs on each trading day during the twenty (3) trading day period immediately prior to such Conversion Date (subject to certain adjustments); provided, however, that the Conversion Price shall not be less
(3) than $2.00. In addition, the Preferred Units are convertible on a one-for-one basis (subject to customary anti-dilution adjustments) by the holders of such Preferred Units at any time following May 31, 2017 so long as any conversion is not for less than $250,000 or such lesser amount, if such conversion relates to all of such Purchaser's remaining Preferred Units. In addition, upon certain events involving a change of control, each holder of the Preferred Units may elect to (a) convert its Preferred Units to Common Units at the then-applicable conversion rate, (b) if the Partnership is not the surviving entity (or if the Partnership is the surviving entity, but its Common Units will cease to be listed on a National Securities Exchange), require the Partnership or the acquiring entity, as applicable, to either (i) deliver a security in the surviving entity that has substantially similar rights, preferences and privileges as the Preferred Units or (ii) redeem each Preferred Unit held by
(4) such Preferred Unitholder at a redemption price per Preferred Unit equal to 120% of the greater of (A) $11.43 and (B) the intrinsic value of the Preferred Units determined as of the applicable date of determination or (c) if the Partnership is the surviving entity and its Common Units continue to be listed or admitted to trading on a National Securities Exchange, continue to hold the Preferred Units.
(5) The issuance of the Preferred Units to CSI Investment and the conversion into Common Units were approved by the Board of Directors of CSI Compressco GP Inc. ("CPGP"), the general partner of the Issuer. Accordingly, the transaction reported on this Form 4 is exempt from Section 16(b) pursuant to Rule 16b-3(d)(1) under the Securities Exchange Act of 1934 (the "Exchange Act").
(6) On September 10, 2018, a Conversion Date, 41,375.20 Preferred Units owned by CSI Investment automatically converted into 85,830 Common Units at a conversion price of $5.51 (as described in (1-4) above) pursuant to the Purchase Agreement without the payment of additional consideration or further action on the part of the reporting person.
(7) All of the reported Preferred Units are owned directly by CSI Investment, a direct, wholly owned subsidiary of CPGP, and may be deemed to be beneficially owned by (i) CPGP, a direct, wholly owned subsidiary of Compressco Field Services, L.L.C. ("CFS"), (ii) CFS, a direct, wholly owned subsidiary of Compressco, Inc. ("CI"), (iii) CI, a direct, wholly owned subsidiary of TTI and (iv) TTI.
(8) The Preferred Units are perpetual in nature and have no expiration date.
(9) Each of the reporting persons may be deemed a "director by deputization" of CSI Compressco LP (the "Issuer") by reason of the fact that all directors of the general partner of the Issuer are designated by TETRA Technologies, Inc. ("TTI").

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